Vine weevil/RHS Gardening Biology What is vine weevil? Vine weevil is a beetle that attacks a wide range of plants, both indoors and outdoors, but is especially damaging to plants grown in containers . It is one of the most widespread, common and devastating garden pests. The adult weevils eat plant leaves during spring and summer, but it is the grubs that cause the most damage over autumn and winter when they feed on plant roots. This damage often results in wilting and plant death. Plants growing in pots and containers, outdoors or under cover, are most likely to be severely damaged by vine weevil grubs. Plants growing in the open ground are less likely to be damaged, although heavy infestations of grubs can occur on strawberries , Primula, polyanthus, Sedum , Heuchera and young yew plants. The adult beetles feed on the foliage of many herbaceous plants and shrubs, especially Rhododendron , evergreen Euonymus , Hydrangea , Epimedium, Bergenia, Primula and strawberry . Adults rarely cause enough damage to affect the vigour of plants.

There are several other species of weevil closely related to vine weevil, the adults of which cause similar damage but are less problematic as larvae. Symptoms You may see the following symptoms: Adult weevils are approximately 9mm (about 5/16in) long and dull black with dirty yellow mark on the wing cases. They cause irregular-shaped notches of leaf margins during the summer The plump c-shaped white legless grubs have light brown heads and are up to 10mm (about 3/8in) long. They are likely to be found among the roots. Plants wilt and die during autumn to spring as a result of grubs devouring the roots Control Gardeners with vine weevil should keep up their guard because stopping control measures after the apparent disappearance of the weevil can allow numbers to build up again. Cultural On mild spring or summer evenings inspect plants and walls by torchlight and pick off the adult weevils. Shake shrubs over an upturned umbrella, newspaper or similar to dislodge and collect more. In greenhouses, look under pots or on the underside of staging benches where the beetles hide during the day. Trap adults with sticky barriers placed around pots or on greenhouse staging.

Encourage natural enemies. Vine weevils and their grubs are eaten by a variety of predators such as birds, frogs, toads, shrews, hedgehogs and predatory ground beetles. Biological A biological control for the larvae is available as a microscopic pathogenic nematode (Steinernema kraussei) available from suppliers of biological controls. This is suitable for use in containers and in the open ground. For best results apply in August or early September when the soil temperature or potting media is warm enough for the nematode to be effective (5-20ºC/41-68ºF) and before the vine weevil grubs have grown large enough to cause serious damage. Another nematode, Heterorhabditis megidis, is also available but is more temperature-dependent (12-20ºC/ 54-68ºF). Both of these nematodes can give poor results in dry or heavy soils. They work best in lighter soils and open potting composts, such as peat or coir. Nematodes can be used safely on all edible and ornamental plants.

A trap containing nematodes (Steinernema carpocapsae), is also available for controlling adult vine weevil. The traps should be placed on the ground below plants damaged by the weevils during the summer. The adults enter the trap during the day and are infected by the nematodes. Chemical Ornamental plants grown in containers can be treated with acetamiprid (e.g. Bug Clear Ultra Vine Weevil Killer) as a liquid drench applied to the compost. This insecticide gives protection against the grubs for up four months; treatment in mid- to late summer will control the young larvae and prevent damage occurring later in the autumn to spring period. This product cannot be used to treat edible plants or ornamental plants growing in the ground. Downloads Biological control suppliers (Adobe Acrobat pdf document) Biology Adult vine weevils cause notch like leaf damage, which can be unsightly but rarely affects plant growth. The adults are 9mm (about 5/16in) long, dull black beetles with a pear-shaped body when viewed from above. Adult weevils may be seen on the foliage at night; during the day they hide in dark places.

They are slow-moving insects that cannot fly but they are excellent crawlers and climbers. There are several other related species found in Britain which can cause similar damage to foliage as adults. Some that have recently become established include Otiorhynchus armadillo, O. crataegi and O. salicicola, cause similar damage to foliage. Far more serious is the damage caused by the soil-dwelling larvae, which are plump, white, legless grubs up to 10mm (about 3/8in) long with pale brown heads. These eat the roots of a wide range of plants and can bore into tubers of cyclamen and begonia, and into stem bases of cacti and succulents. They can kill woody plants by gnawing away the outer tissues of the larger roots and stem bases. Most plant losses occur during September to March, when the grubs are becoming fully grown. All Otiorhynchus sulcatus adults are female and each can lay several hundred eggs during spring and summer. The eggs are brown and less than 1mm (about 1/16in) in diameter, making them very difficult to see in soil.

Larger yellowish-brown spherical objects seen in potting composts are likely to be controlled-release fertiliser pellets added by the nursery that raised the plants. ‹ › Vine weevil larvae, showing their small brown heads and C-shaped, legless bodiesVine weevil pupae close to developing into adultsVine weevil grubs feeding on cyclamen tuberRhododendron leaves showing typical adult vine weevil notching around the margins See also... Vine Weevils | LoveTheGarden.com Vine Weevils Vine Weevils Vine weevils are a devastating plant pest – suddenly otherwise healthy looking plants wilt and collapse and no amount of watering will help them recover. The reason? The vine weevil grubs have eaten all the roots. Description Vine weevil grubs are particularly rampant in containers, but they also attack plants in borders and beds, where dealing with them is far more difficult. The real danger is the underground grub - you can’t see what they’re doing until maybe it’s too late. Symptoms Vine weevil grubs Baby vine weevils grow from little eggs laid in the plant’s roots - which are very difficult to see.

They hatch into 10mm long ‘C’ shaped grubs with cream coloured bodies and brown heads. The little vandals, unseen, simply munch away at the root system until either they are caught or the plant first yellows, then wilts and collapses through lack of sustenance. Adult vine weevils are dusty grey/black flightless beetles. They are all female and each can lay up to 1,000 eggs in a season. Eggs are laid during the summer and early autumn ready to become grubs in spring the following year. These beetles do most of their eating at night and restrict themselves to nibbling away at the edges of leaves. The results are unsightly but not life-threatening to the plant. However the energy they get from eating ensures that the eggs will be laid. So they can’t be ignored. Treatment and Control General tips Adult Vine Weevils are pretty resistant to sprays. It is best to physically remove them. Collect them, by torchlight, at night whilst they are feeding. Place a newspaper, a tray or something else that will catch these flightless beetles and ‘knock’ the plant to dislodge them. Pick them up, squash them and bin them.

Drench the compost It is possible to kill the adult larvae that feed on plant roots by drenching the compost in which ornamental plants are growing with a systemic insecticide. Treating edible crops Weevils - Weevil Facts & Control Information Weevils Weevils: Facts, Identification & Control What Are Weevils? Weevils are actually beetles. Most belong to the family Curculionidae. There are more species in this family than in any other beetle group. Scientists estimate that there are over 1,000 species of Curculionidae in North America. Weevil species occur in a wide range of colors and body shapes. Many are slender or oval-shaped insects. Depending on the species, weevils range in size from about 3 mm to over 10 mm in length. They are usually dark-colored—brownish to black. Some have scales or shiny hairs covering part of their bodies. The most distinctive feature of weevils is the shape of their head. An adult weevil has an elongated head that forms a snout. The mouth is at the end of the snout. Some weevils have a snout that is as long as the body.

Another family of beetles called Bruchidae, such as the cowpea weevil, have a different appearance from the typical weevil. They lack the elongated snout found in the Curculionidae. What Do Weevils Eat? Weevils feed on plants in the larval stage and as adults. Some weevils can be very destructive to crops. For many years, one of the most destructive weevils was the cotton boll weevil. The black vine weevil , Otiorhychus sulcatus (F.), is found in many parts of the United States. It feeds on a variety of plants, including hemlocks and rhododendrons. Most weevils are found in fields, gardens or orchards. A few weevils attack stored grains and seeds. They can be very destructive, and their damage is often very expensive. The most common stored product weevils are the rice weevil, Sitophilus oryzae (L.), the granary weevil, Sitophilus granarius (L.), and the cowpea weevil , Callosobruchus maculatus (F.). However, a few weevils become structural pests.

These are the weevils that upset homeowners because they invade homes—often in great numbers. Some of them invade in the fall. They hide during the winter and leave in the spring. Others invade in the summer when the weather starts turning hot. Weevil Life Cycle Life cycle of weevils depends greatly on the species. For some, in spring, the adult weevils lay their eggs on the ground near the host plant. When the eggs hatch, the larvae burrow into the ground and feed on the roots. Since the larvae are underground, people seldom see them. Many of the larvae spend the winter in the ground and emerge as adults the following spring. However, the adults that emerge during the summer or fall may invade homes for shelter. Some, like the Asiatic oak weevil, are attracted to light, so they are drawn to homes at night. Others may be attracted by the warmth from the house. Weevil Control Homeowners might not notice weevils when they are gathered on the outside of the home. But if the weevils manage to find an opening and invade the home, the homeowner often finds hundreds of insects crawling on the walls and windowsills.

A vacuum cleaner is a quick way to remove weevils from the walls and furniture. Be sure to take the vacuum outside to empty it so the weevils don’t reinfest the home. If weevils haven’t invaded, there is time for some prevention. Check outside for any openings that weevils could use to get inside. Look around doors and windows for missing caulk and damaged weather stripping. Check attic vents and crawl space vents for torn screens. Most likely, homeowners seeing weevils are dealing with the stored product species. The most important control methods are to find the infested material and eliminate it. Careful inspection of items before purchasing can help prevent getting a new infestation. Products with holes or signs of damage on the packaging should not be purchased. The Orkin Man™ can help homeowners manage weevils. He will use Orkin’s exclusive A.I.M. system—Assess, Implement and Monitor. He will design a treatment plan for your home’s situation. By focusing on the source of the problem—outside or inside of the home—he will be able to help keep weevils from invading again. When weevils invade , they can come in large numbers.

Homeowners often feel more confident calling the local Orkin branch office to get The Orkin Man™ to help get weevils out of their home and keep them out. Types of Weevils Boll Weevil —The boll weevil (Anthonomus grandis) is a type of beetle that is known to cause severe damage to cotton crops. The boll weevil measures an average length of 6 mm. It feeds on the buds and flowers of the cotton plant. Flour Weevil —Wherever flour is present, the beetle known as the flour weevil (Family Tenebrionidae) follows. They are not able to feed on whole grains. These beetles are not actually weevils. Rice Weevil —While it is true that the rice weevil (Sitophilus oryzae) is harmless in itself, it hurts human beings on a larger magnitude by compromising food supplies. What it lacks in stinging or biting, it makes up for in causing destruction on a potentially massive scale. Bean Weevil — is the scientific name of The bean weevil (Acanthoscelides obtectus) the farmers’ scourge.

Technically, they belong to the cadre of seed beetles and are not true weevils. Wheat Weevil —Commonly called the granary weevil, the wheat weevil (Sitophilus granarius) holds notoriety for its destructive potential in agriculture. Historically, it is known as one of the most formidable pests. Black Vine Weevils —The black vine weevil (Otiorhynchus sulcatus) is believed to be another species that migrated to the United States. Rose Weevil —The rose weevil (Merhynchites bicolor) is a serious threat to all horticulturists. Its snout can drill through flower buds. These weevils cause irreparable harm by feeding on petals. White Pine Weevil —The white pine weevil (Pissodes strobi) is a pest that infests pine and spruce trees. Cowpea Weevil —True to its name, this pest infests cowpeas and stored soybeans. Cowpea weevils (Callosobruchus maculatus) lay eggs on the stored beans that they eat, and the larvae use the beans as food while they develop.

More facts about weevils: Vine Weevil Control | Garden Pests | GardenForum Horticulture Suppliers Vine weevil is a garden plant pest problem that can be difficult to control. Gardeners with vine weevil will need to take measures to control them. Vine weevil is one plant insect pest that most gardeners live in fear of. And it is a pest to worry about. Suddenly, otherwise healthy-looking plants collapse and die thanks to the root-eating, soil-borne grubs. You should suspect a vine weevil attack if watering does not revive the plant. In severe cases, plants may be completely severed from their roots at ground level. In the past, their favourite food was fuchsias, cyclamen, begonias and primulas. But in recent years they have become less fussy and will make a meal of a much wider range of plants - especially any that are growing in containers. This is possibly due to the use of peat-based and peat-free composts - being less gritty than John Innes composts, the adults are more likely to lay their eggs in them. What to do if you notice a vine weevil attack?

Don't despair, there are several ways of dealing with this plant-nibbling nasty. It is important to be vigilant and keep a close eye on all your plants - especially those that are known to be favourites on the menu. Always check the rootballs for grubs before you buy plants. Check when potting up or repotting plants, and destroy any that you see; it usually pays to dispose of affected compost too. Because vine weevil is such a destructive pest, every effort must be taken to control both the adults and the soil-borne grubs. There are three ways of controlling vine weevil: chemical, biological control and physical barriers. Controlling vine weevil grubs Typical vine weevil grubs, which will eat the roots of a wide range of different plants. They are creamy-white, up to 13mm (0.5in) long, C-shaped, with a brown head and no legs. Often the first signs of damage are only spotted when a plant completely wilts and dies. Commercial nurseries may sometimes add chemicals to the compost to control them. It is always worth asking when you are buying particularly susceptible plants if any such chemicals have been used.

There are a number of insecticides that can be used to treat plants and give protection against attack. Bayer Garden Provado Vine Weevil Killer 2* and Scotts BugClear Ultra Vine Weevil Killer are systemic insecticides that can be used for any container-grown plants (apart from edible ones); they are watered onto the compost. Bayer Garden Provado Ultimate Bug Killer* and Scotts BugClear Ultra are also systemic and are sprayed onto plant foliage to kill leaf pests, but may also give some control of vine weevil grubs (some edible plants can be treated; check the label first). Use plant protection products safely. Always read the label and product information before use. If you don't like using pesticides, use a biological control based on nematodes. These microscopic creatures enter the bodies of the grubs and release a specific bacteria that poisons and kills them. They then multiply and go on to attack other grubs. The nematodes are available from several mail order supplies, such as Defenders, Scarletts PlantCare, Just Green and Green Gardener. See the suppliers list for details.

* In 2016, Bayer Garden changed the active ingredient in Provado Ultimate Bug Killer to one that doesn't have a systemic action. The company also stopped selling Provado Vine Weevil Killer 2. Controlling vine weevil beetles Typical vine weevil beetle damage to rhododendron leaves... ..and a typical vine weevil adult beetle. One of the most effective - but time-consuming - methods of controlling the adult vine weevil beetles is to check your plants at night when they are active and feeding. They can then be scooped up and disposed of. Another way is to use a physical barrier as the adult beetles cannot fly from plant to plant. Stand potted plants on upturned pots sat in saucers of water - the adults can't swim. Or surround the pots with Barrier Glue available from Agralan - the adults cannot walk across it. With either of these methods it is important to move plants away from walls or greenhouse/conservatory walls as the adults can jump down onto them; they cannot fly. Physical barriers on top of the soil or compost also work very well.

Add a 2cm (0.75in) deep layer of sharp grit or gritty gravel on top of the compost or around the base of the plant to prevent the adults from laying eggs; the egg-laying structure is irritated by the scratchy feel. Vine weevil eggs All vine weevil adults are female, and each one can lay hundreds to thousands of eggs from April to September; the main egg-laying periods are April and August/September. If you spot golden-brown or clear egg-like objects in the soil or compost then they're NOT vine weevil eggs. Vine weevil eggs are brown and tiny and you'd need a hand lens to see them. Clear spheres are usually slug or snail eggs and the golden-brown ones are actually controlled-release fertiliser!

Suppliers Buy a range of pest control products, inluding biological controls, from my affiliate companies, Harrod Horticultural and Greenfingers.com Agralan , The Old Brickyard, Ashton Keynes, Swindon, Wilts SN6 6QR; sales@agralan.co.uk (barrier glue) Bayer Garden , 230 Cambridge Science Park, Milton Road, Cambridge CB4 0WB; gardening.adviser@bayergarden.co.uk (Provado) Biowise , Hoyle Depot, Graffham, Petworth, West Sussex GU28 0LR (biological controls) Defenders , PO Box 131, Ashford, Kent TN25 5EN; info@defenders.co.uk (nematodes) Green Gardener , Chandlers End, Mill Road, Stokesby, Great Yarmouth NR29 3EY (nematodes) Just Green , Unit 14, Springfield Road Industrial Estate, Burnham-on-Crouch, Essex CM0 8UA; (nematodes) sales@just-green.com Organic Gardening Catalogue , Riverdene Business Park, Molesey Road, Hersham, Surrey KT12 4RG (var

ious products including biological controls) Scarletts Plant Care , The Glasshouses, Fletching Common, Newick, Lewes, East Sussex BN8 4JJ (biological controls) The Natural Gardener , The Steppes, Hope under Dinmore, nr Leominster, Herefordshire HR6 0PP (biological controls) The Scotts Miracle-Gro Company , Salisbury House, Weyside Park, Catteshall Lane, Godalming, Surrey GU7 1XE; consumerenquiriesuk@scotts.com (BugClear Ultra) If you want to know more, or if you've got a gardening problem you need help with, then send an e-mail to: info@gardenforumhorticulture.co.uk Vine weevils - Pests - Diseases Professional area | Diseases factsheet | Pests | Vine weevils Pests Vine weevils The Otiorrhynchi are a kind of weevil: The Black Vine Weevil O.

sulcatus and the Cyclamen Weevil O. rugosostriatus are the worst pests on cyclamen. The damage is done partly by the leaf-eating adult, brown to black in colour and some 6 mm long, and partly by the larvae which feed on the rootlets and main roots at the base of the cyclamen bulb. The glasshouse climate enables this sort of beetle to develop at any time of year. Chemical control is not easy, since adults and larvae require separate treatment, and resistance has already become apparent. Preventive treatment, such as the use of bagged commercial compost, weed control in the surrounding areas and removal of rotting plant material, considerably reduces the risk of infestation. Biological control is a useful alternative to chemicals. Summary Chemical control > Classification Vine weevils belong to the family Curculionidae (weevils) in the superfamily Curculionoidea of the order Coleoptera (Beetles). They are round weevils. O.sulcatus, the Black Vine Weevil, is the kind most often found under glass; it is a pest of many ornamental plants as well as cyclamen. Other species encountered are O. singularis, O.

lugdunensis, O. ovatus and O. rugosostriatus. Two forms of damage are done: firstly, by the adults feeding on the leaves secondly, by the larvae underground attacking the root system. > Stages of development and body features The Vine Weevil’s development has 4 stages: egg pupa adult The genus Otiorrhynchus includes a number of species characterised by a head with a beak and mouth parts at the end of this beak, and the antennae in the middle of it. It also has bent wings and a curved abdomen. 1 > O. sulcatus The first adults usually appear in April or May. They are brownish-black, shiny, dotted with yellow patches on the back, and around 1 cm long. They have a stubby beak, with the typical bent antennae rising from its base. The adults’ wing-cases are deeply channelled. They do not fly, as like all coleopterans they have no wings; they have 6 legs, and are hard to make out against the background of compost or soil. Reproduction is asexual (parthenogenetic). In northern Europe there are only females.

They lay eggs in the growing medium from July to late October, and one female can lay from 100 to 1000 eggs. The laying season lasts longer under glass. The eggs are white, round and 0.7 mm in diameter. The egg hatches into a larva after 10 to 25 days. These legless larvae are whitish pink with a chestnut coloured head and live in the ground for 2 to 12 months, reaching a full length of 1 cm. This is the form in which they over-winter. As soon as the temperature rises, the larva becomes active again and becomes a nymph or pupa in the spring, spending 20 days or so in this stage (still in the soil) before emerging as a new female adult, which lives for 5 to 12 months. Outdoors there is one generation each year; but in the glasshouse each of the stages may be present at any time: there is no hibernation. 2 > O. rugosostriatus (Cyclamen Vine Weevil) The adult is reddish- to blackish-brown and 6 mm long.

It is oval in shape, and very similar to O. sulcatus, with the same life cycle. Eggs are laid in the ground from May to July, and the larvae go into the nymph stage in January. > Damage seen on cyclamen following weevil attack Both adults and larvae cause visible damage to cyclamen, but it is the larvae which do the most harm. They are active day and night, while the adults only feed by night, hiding during the day under plant litter, planks and pots, as well as in the heart of the plant. > Root damage The small larvae feed on rootlets, while the larger ones eat the main roots at the base of the bulb. Even the corms themselves may be gnawed. These attacks cause growth to stop and the leaves to go yellow, ending with wilt all over. Just one or two larvae in a pot can be fatal for the cyclamen. > Leaf damage From springtime on, the adults feed on the leaves starting at the edges. The bites show as characteristic nicks (which spoil the plant’s appearance considerably) and the leaf margin has a wavy look. This damage may be seen from August until the end of the growing season.

The adults also sometimes eat the soft petals. > How vine weevils spread The adults may not fly, but they are great walkers. They can feed on many different kinds of plant, and so spread far and wide: the first thing to do therefore is to examine any imported plants, as well as those already in the glasshouse, and check they are free of infestation. > Countermeasures Larvae and adults require separate treatment if they are to be controlled effectively. The adults are hard to combat since they are active for such a long period, while chemical control of the larvae is made harder by their resistance to many insecticides. Nevertheless effective control is possible by using insecticides mixed in with the compost. > Biological control Biological methods are a useful alternative to chemical control. They use a nematode (eelworms) parasite of the larva. The most active of these little round worms for this purpose are those of the order Rhabdita, in the Steinernematidae and Heterorhabditidae families. A number of these families’ species attack vine weevil larvae, but the best results to date have been with Heterorhabditis sp. (such as H. megidis).

Steinernema feltiae also gives good results against larvae. 1 > Infecting the pest These nematodes develop in 4 stages, two of which are directly involved in weevil eradication. The first larval stage develops without hatching, right in the egg; it plays no part in the infection process. The second larval stage then leaves the egg, but is not infectious either: it is the larvae of stage 3 that are infectious and actively seek out their host, penetrating the larvae by means of their natural body orifices and through the epidermis. The nematode larvae contain bacteria (Xenorhabdus sp) in their gut, which then spread to the weevil larva and there multiply. The weevil larva goes brown and dies of septicaemia within 48 hours. The bacteria are symbiotic with the nematode larvae, breaking down the weevil larva’s tissues into a form that the nematode larvae can assimilate. These larvae then set off in search of a new host. The final larval stage of the nematode infects the adult weevil, developing inside it into a hermaphrodite adult nematode, which lays an egg in its host.

The surviving eggs produce male and female individuals which mate, and the eggs that the females then lay begin a new cycle of infection. 2 > Commercial preparations available in France (Plant Medication Index 1997) Heterorhabditis megidis nematodes are delivered in the third larval stage on an inert medium, under the name Larvanem. After about a week, weevil larvae will be parasitised. The procedure requires high humidity and a soil temperature of around 15ºC (59ºF) for success; above 27ºC (81ºF) the nematodes’ effect falls off. The product Nemasys is applied as a spray. The nematodes are supplied at the adult or larval stage. 5000 nematodes are needed per litre of compost. Steinernema feltiae, a nematode parasite of Leafminers, gives good results according to a report from Holland. The commercial preparations are Nemasys, Nemasys-M, Exhibit SF WDG, Entonem. Steinernema carpocapsae is active against vine weevil, also; it is sold under the name Exhibit SC-WDG.

3 > Moulds There is also an effective gut pathogen mould (Metarhizum anisopliae). Good results have also been obtained with the combination of a mould, Beauveria brongnartii, and the nematodes Heterorhabditis sp. > Chemical control The constant development of the regulations and homologations of phytosanitary treatment products, and the differences in regulations according to each country make it impossible for us to include updated information on homologations. Each producer will have to contact his local plant protection bureau to obtain the latest updates concerning the regulations and use of phytosanitary products. We strongly advise testing beforehand on a plant sample in order to measure the chemical’s activity (establishing the dose) and any effect on the plant (plant poisoning). Steam disinfecting of soil and compost destroys this pest at all stages. 1 > Treatment against adults Treat as soon as the adults appear (April, May) and continue fortnightly until September, using a wettable powder and large quantities of water, preferably at night. 2 > Treatment against larvae The larvae are treated in watering the soil or mixing micro granules in with the growing medium.

Caution This advice sheet is based on the methods used at the SCEA at Montourey (Fréjus, France). These procedures may need some modification to adapt them to other climatic situations. Before starting to grow cyclamen there needs to be a review of precautions against pests and diseases. We must point out that our advice and suggestions are offered for information purposes and therefore cannot include any guarantee of specific results; it is a good idea to carry out trials beforehand. Vine weevil control: how to get rid of vine weevils - Saga Vine weevils can cause devastating damage in your garden. Find out what you can do to protect your plants. Hear no weevil, see no weevil, speak no weevil Close Hear no weevil, see no weevil, speak no weevil The vine weevil is a tiny root-eating grub capable of devastating damage underground. It can cause plants to yellow, wilt and eventually keel over as the last roots have been gnawed through. If you think you’ve got vine weevil in the garden take action now to safeguard your plants from this pernicious pest. What do vine weevils look like? Adult vine weevils are black and about 1cm long.

They lay eggs in soil from March to September, which hatch into white, C-shaped grubs that feed voraciously. How to spot vine weevil damage You know you’ve got vine weevils in the garden if you spot small, irregular notches around the outside of leaves. This is caused by adult beetles, which mainly feed at night on a whole host of plants including euonymus, bergenia and hydrangea. This damage is largely cosmetic, rather than life threatening to plants. Plants grown in pots are vulnerable to vine weevil grubs, which eat roots beneath the soil. You often won’t realise there’s a problem until the plant topples over due to all its roots being severed. Cactus, succulents, cyclamen, begonia, heuchera and many other plants are open to attack. Where to find vine weevils Vine weevil adults can often be found hiding under the base or lip of pots, so check regularly and squash any you find. Another technique used by some gardeners is to go out at night with a torch and shine it on the leaves of vulnerable plants, where you might spot the beetles feeding.

Adult vine weevils love to lurk under debris, so pick up fallen leaves and sweep up in the greenhouse to reduce the number of places they can conceal themselves. Chemical control of vine weevils Protect your pots by drenching the compost with a pesticide, Bio Provado Vine Weevil Killer 2. It can be mixed with water and applied with a watering can, protecting plants for up to four months. The product is widely available from garden centres and can be used on pots all year round. Biological control of vine weevils If you don’t want to use chemicals, try Nemasys Vine Weevil Killer. This contains microscopic creatures called nematodes that are a natural enemy of vine weevils. The product is available from some garden centres, but has to be kept it in a fridge. Pop it into a watering can, mix with water and sprinkle it on. This can be used for protecting pots or other parts of the garden. It can be used in greenhouses all year round, but is best applied in early spring or autumn outside. The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation. Related Articles Control Control of these insects has become more difficult with the withdrawal of many of the persistent organochlorine- based insecticides. Current insecticidal control in soft fruit is by application of sprays or drenches of a small number of products (consult your fruit advisor for up-to-date recommendations). Nematodes as a biocontrol method have been investigated, although they have been found to be ineffective in cooler climates. A suitable control method for vine weevils is currently being sought. Clay-coloured Weevil Introduction The Clay-coloured weevil (Otiorhynchus singularis) (shown left) is locally important pests in raspberry plantations in east and central Scotland. Unlike the vine weevil, most damage to raspberry is caused by feeding of adult weevils in the spring. These weevils have a much narrower host range than vine weevil. They feed on hardy ornamental shrubs, most notably, rhododendrons and raspberry.

These weevils have a similar geographic range to vine weevil and have recently been found feeding on raspberry in North-west USA. Also, like vine weevil, all the adults appear to be parthenogenic females. Click on image to enlarge Damage Raspberry: The most noticeable damage to raspberry is adult feeding to the buds and expanding fruiting laterals in the spring, and to newly planted canes. These animals feed after dark and have been observed on the cane when the air temperature was 4ºC. Most severe damage occurs when weevils emerge early in the season and feed on the expanding buds. If the secondary buds are also chewed, then yields can be severely affected. Later emergence results in a different form of damage. Adult weevils frequently chew the petioles of the expanding flower laterals. These subsequently break either in strong winds or by the increasing weight of the developing flowers and fruit. There is no evidence to show that larval feeding to the roots causes any noticeable loss of yield. Image of adult clay-coloured weevil feeding on raspberry fruiting lateral at night. Note damage to leaflets and to main lateral.

Severe damage to young fruiting laterals (right) caused by early attack by clay-coloured weevil in the spring. Cane on left not attacked. Hardy Ornamental Nursery Plants: Adult feeding damage to perennial plants, such as rhododendron, is very similar to that caused by vine weevil and consequently much of the damage may be wrongly attributed. The most common symptom is notching on leaves, particularly those closer to the ground. There appears to be no significant damage caused by larval feeding. Notching on rhododendron leaves caused by clay-coloured weevils Life Cycle Laboratory studies at SCRI have shown that the adults have the potential to live for one or two years. Given an adequate food supply adult have several periods of egg laying in any one year. They have also the potential to lay in excess of 100 eggs per annum. Clay-coloured weevil adults emerge in early spring. They climb up the plant after dark and feed on developing buds and flower shoots. They shelter in the soil and debris at the base of the plant. Eggs are laid in the soil and soon hatch. The larvae feed on the roots, often at the depth of about 50 cm.

When fully mature, they pupate in earthen cells and emerge as adults. Clay-coloured weevil eggs Information to Identify And Control Root Weevils Image by David Evans By Heather Rhoades Root weevils are a plant pest both indoors and outdoors. These destructive little insects will invade the root system of a healthy plant and then proceed to eat the plant from the roots up. Identifying and controlling root weevil in your garden and houseplants can keep your plants from suffering unnecessary damage. Identifying Root Weevils Root weevils can be one of several kinds. The most common in the garden is the black vine root weevil or the strawberry root weevil. The black vine weevil attacks shrubs and strawberry weevils attack strawberries . While these are the most common, they are far from the only kind. All plants in your home or garden are susceptible to weevil infestation. Larval root weevils will look like white grubs or worms and will be found in the soil. Adult weevils are beetle like insects that can be black, brown or grey. If root weevils are present in your garden or houseplants, there will be damage to both the roots and the leaves.

The leaves of the plant will be irregular, as though someone has been taking bites out of the edges. This damage will appear in the night, as root weevils come out to feed at night. Root Weevil Control Controlling root weevil is possible. Organic root weevil control methods include purchasing parasitic nematodes or predatory beetles can be bought to hunt down the weevils. You can also hand pick the adults off the plant at night while they are eating. Weevils are also attracted to moisture, so a shallow pan of water can be set out at night and the weevils will climb into it and drown. Non-organic root weevil control methods are to spray the leaves of the plant with a pesticide and to thoroughly soak the soil with a liquid pesticide. But, remember, when you do this, you may also be killing off beneficial insects and small animals as well. Finding these insects in the roots and leaves of your plants is unpleasant, but it can be fixed. As always, the best root weevil control is to make sure you never get any in the first place. Be sure to practice good garden hygiene and clean up dead plants and do not over mulch.

Question: Vine weevils attack which part of a plant?
Answer: The roots